Install GitLab By Using Docker

GitLab is a popular DevOps platform that provides a complete suite of tools for managing your software development lifecycle. It includes features like version control, CI/CD pipelines, and project management, making it an important tool for many development teams. In this article, we will walk you through the steps to install GitLab using Docker.

Prerequisites

Before you begin, make sure you have the following:

• A system with Docker and Docker Compose installed.
• At least 4 GB of RAM (recommended for small to medium GitLab installations).
• Basic knowledge of Docker commands.

Why Install GitLab Using Docker?

Using Docker for your GitLab installation offers several advantages:

• Ease of Setup: Docker simplifies the installation process with fewer configuration steps.
• Portability: Docker containers make it easy to move your GitLab instance across environments.
• Isolation: Docker containers run independently of the host system, reducing the risk of conflicts.

Steps to Install GitLab Using Docker

Step 1: Install Docker and Docker Compose

If you don’t have Docker and Docker Compose installed, follow these commands to install them:

1. Install Docker:

   sudo apt-get update
   sudo apt-get install docker-ce docker-ce-cli containerd.io

2. Install Docker Compose:

   sudo curl -L "https://github.com/docker/compose/releases/download/1.29.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
   sudo chmod +x /usr/local/bin/docker-compose

3. Verify the installation:

   docker --version
   docker-compose --version

Step 2: Pull the GitLab Docker Image

GitLab provides an official Docker image that you can pull from Docker Hub:

docker pull gitlab/gitlab-ce:latest

This command pulls the latest Community Edition (CE) of GitLab. You can also pull the Enterprise Edition (EE) if you have a valid license by replacing gitlab-ce with gitlab-ee.

Step 3: Configure and Run GitLab with Docker Compose

Create a directory for your GitLab setup:

mkdir -p ~/gitlab
cd ~/gitlab

Inside this directory, create a docker-compose.yml file with the following content:

version: '3.7'
services:
    gitlab:
        image: 'gitlab/gitlab-ce:latest'
        container_name: gitlab
        restart: always
        hostname: 'gitlab.example.com'
        environment:
            GITLAB_OMNIBUS_CONFIG: |
                external_url 'http://gitlab.example.com'
      ports:
          - '80:80'
          - '443:443'
          - '22:22'
      volumes:
          - './config:/etc/gitlab'
          - './logs:/var/log/gitlab'
          - './data:/var/opt/gitlab'

Explanation:

• Image: The official GitLab Community Edition Docker image.
• Hostname: Replace gitlab.example.com with your preferred domain or IP address.
• Ports: The setup exposes ports 80 (HTTP), 443 (HTTPS), and 22 (SSH) for GitLab.
• Volumes: Data persistence is important for GitLab. The configuration stores configuration files, logs, and data outside the container.

Step 4: Start GitLab with Docker Compose

Run the following command to start GitLab:

docker-compose up -d

This command runs GitLab in detached mode (in the background). It may take a few minutes for GitLab to initialize and be ready.

Step 5: Access GitLab

Once the container is up and running, you can access GitLab by visiting http://<your-domain-or-ip> in your web browser. The first time you log in, you’ll be prompted to set the root password.

Step 6: Configure GitLab (Optional)

After setting up GitLab, you can further configure it according to your needs:

• Admin Area: Access the admin area by logging in with the root user and clicking on the profile picture in the top-right corner.
• Email Configuration: You can set up email notifications by editing the GITLAB_OMNIBUS_CONFIG in your docker-compose.yml file.
• Backup and Restore: Ensure that your data volumes are regularly backed up to avoid data loss.

Managing GitLab with Docker Commands

Here are some useful Docker commands for managing your GitLab instance:

• Stop GitLab:

  docker-compose down

• Start GitLab:

  docker-compose up -d

• View Logs:

  docker-compose logs -f

• Update GitLab: To update GitLab, pull the latest image and restart the container:

  docker-compose down
  docker pull gitlab/gitlab-ce:latest
  docker-compose up -d

Troubleshooting Common Issues

1. Ports Already in Use: If ports 80, 443, or 22 are already in use, either free up the ports or modify the port mappings in the docker-compose.yml file.
2. Slow Performance: Ensure your server meets the recommended resource requirements. Insufficient RAM or CPU can cause GitLab to run slowly.
3. Permission Issues: Make sure the directories used for data persistence have the correct permissions. You can adjust this with:

   sudo chown -R 1000:1000 config/ logs/ data/